The Messenger of Allah ﷺ forbade me to wear a ring on this or this, ʿAbdur-Razzaq said: meaning his forefinger and middle finger.
نَهَانِي رَسُولُ اللهِ ﷺ أَنْ أَجْعَلَ الْخَاتَمَ فِي هَذِهِ أَوْ فِي هَذِهِ قَالَ عَبْدُ الرَّزَّاقِ لِإِصْبُعَيْهِ السَّبَّابَةِ وَالْوُسْطَى